Whales, Dolphins, and Porpoises of the Western North Atlantic Part 6

Body to at least 17.5 feet (5.3 m) long.

Body black with indistinct light gray area on chest; saddle behind dorsal fin.

Head becoming more bulbous with age; square in large adult males viewed from above.

Flippers relatively short (to less than one-sixth of body length).

Dorsal fin broad-based, falcate to flaglike, in front half of back.

Distribution tropical and warm temperate; from about Hatteras south.

Flukes not usually raised on dive.

[Sidenote: GRAMPUS

_Grampus griseus_

p. 96]

Body to at least 13 feet (4.0 m) long.

Body of newborn light gray; darkens with age.

Body of adults light gray or white; scarred with numerous scratches.

Head blunted, not beaked.

Forehead has vertical crease in center.

Dorsal fin less than 15 inches (38.1 cm), rather erect and distinct, and dark even in light adults.

Distribution tropical to temperate.

Rarely ride bow wave.

(13-16 feet [4-5 m] maximum overall length)

Without a Dorsal Fin

The only two species of medium-sized cetaceans in the western North Atlantic which have no dorsal fin, the Beluga or white whale and the Narwhal, share such limited common range, well outside the theater of normal boating traffic, that they are generally infrequently encountered.

Both species are easily identifiable when seen.

[Sidenote: BELUGA

_Delphinapterus leucas_

p. 99]

Body to 16 feet (4.9 m) long.

Body of adults all white; young slate gray.

Small row of b.u.mps along back ridge near midpoint, sometimes dark brown.

Distribution usually near coast from Arctic waters to St.

Lawrence Gulf and into Hudson Bay.

[Sidenote: NARWHAL

_Monodon monoceros_

p. 102]

Body to 16 feet (4.9 m) long.

Body of adult brownish with grayish spots; body of young dark bluish gray fading to white belly.

Head small; adults may have tusks up to 9 feet long (2.7 m).

Small row of b.u.mps along back ridge.

Distribution usually in coastal waters from Arctic waters south to Labrador coast.

SMALL WHALES, DOLPHINS, AND PORPOISES

(less than 13 feet [4 m] maximum overall length)

With a Dorsal Fin

The species in this group are not discussed in order of length; instead the species of the genus _Stenella_ are treated together and then they and other species are placed in near proximity to those animals with which they are likely to be confused in the field.

[Sidenote: ATLANTIC SPOTTED DOLPHIN

_Stenella plagiodon_

p. 104]

Body to 7.5-8 feet (2.3-2.4 m) long.

Body dark purplish gray on back, lighter gray on sides and belly; becomes increasingly spotted with increase in size.

Body has spinal blaze and light line from flipper to eye.

Beak white on tip.

Rides bow waves.

Distribution usually in tropical and warm temperate waters; most common inside 100-fathom curve of continents.

[Sidenote: BRIDLED DOLPHIN

_Stenella frontalis_

p. 108]

Body to at least 7 feet (2.1 m) long.

Body dark gray on back; lighter gray on sides and belly.

Body has no spinal blaze.

Cape on top of head distinct.

Bridle: dark lines from eye to rostrum and from flippers to corner of mouth.

Rides bow waves.

Distribution in tropical waters, primarily in West Indies.

[Sidenote: SPINNER DOLPHIN

_Stenella longirostris_

p. 110]